The invention is in the field of lawn sprinklers, and in particular a class of sprinklers of a lawn-decorating type in which a sculpture-like sprinkler head is rotatably mounted at the top of a vertical stand pipe connected to a water supply.
There is a class of lawn sprinklers known for their sculpture-like ornamentation of lawns. These sprinklers generally comprise a sprinkler head made from hollow metal tubing bent or formed into graceful, artistic designs. The sprinkler head is mounted on the end of an upright standpipe, usually several feet in height. The standpipe is supported on a base secured to the lawn, and connected to a water supply through a garden hose.
The decorative sprinkler heads are intended to rotate, both to provide uniform coverage and often to create a decorative spray effect. The rotation is created by the force of water exiting spray holes perforating the hollow tubing of the sprinkler head.
It is accordingly necessary to provide a rotatable connection between the sprinkler head and the upper end of the standpipe. This connection is usually in the form of a multi-part bushing which rotatably connects the sprinkler head to the standpipe and provides a passage for water from the standpipe to the sprinkler head. Such multi-part bushings typically suffer from two problems: they leak, and they do not provide a sufficiently strong connection between the sprinkler head and the standpipe. Another problem encountered with some of these bushings is the need to braze or weld them to the standpipe.
The invention is a three-part adapter bushing for connecting a decorative, tube-type sprinkler head to the upper end of a vertical standpipe, in rotating manner, without leaks, without tendencies to loosen, and without requiring a permanent weld. The first part is a cup-like base which rests on the upper annular edge of the standpipe. The second part comprises a stem having a lower end which seats in rotatable, sealed fashion inside the cup-like base, and an upper end adapted to be secured to the sprinkler head.
The third part comprises an oversleeve which fits over both the cup and the stem rotatably contained in the cup to be removably secured to the upper end of the standpipe, preferably by threaded connection.
The cup-like base is axially sealed with respect to the upper, annular edge of the standpipe. The lower end of the stem is radially sealed with respect to the cup. As the oversleeve is threaded down over the cup/stem combination, the oversleeve engages the radial seal between the lower end of the stem at the cup-like base, and further places the axial seal between the cup-like base with the upper end of the standpipe under compression.
The upper end of the stem protrudes from the oversleeve when the over sleeve is secured to the standpipe, for connection to the sprinkler head. In a preferred form, the upper end of the oversleeve provides a rotatable bearing surface for a portion of the sprinkler inserted over the upper end of the stem. Accordingly, when the sprinkler head is secured to the upper end of the stem, in preferred form by a set screw engaging a groove in the upper end of the stem, the stem rotates with the sprinkler head on the cup-like base on the standpipe inside the over sleeve, without leaking, and without working loose.
These and other features and advantages of the invention will become apparent upon further reading of the specification in light of the accompanying drawings.